BFD holddown is the right feature for this. WARNING: BFD holddown is known to be problematic between Juniper and Cisco implementations due to where each start their state machines for BFD vs. BGP.
It was a partial motivation for BGP BFD strict: https://datatracker.ietf.org/doc/html/draft-ietf-idr-bgp-bfd-strict-mode BGP BFD strict was added in 23.2R1. -- Jeff On 4/28/24, 05:13, "juniper-nsp on behalf of Thomas Bellman via juniper-nsp" <juniper-nsp-boun...@puck.nether.net <mailto:juniper-nsp-boun...@puck.nether.net> on behalf of juniper-nsp@puck.nether.net <mailto:juniper-nsp@puck.nether.net>> wrote: [External Email. Be cautious of content] Juniper Business Use Only On 2024-04-27 09:44, Lee Starnes via juniper-nsp wrote: > Having difficulty finding a way to prevent BGP from re-establishing after a > BFD down detect. I am looking for a way to keep the session from > re-establishing for a configured amount of time (say 5 minutes) to ensure > we don't have a flapping session for a. link having issues. Isn't that what the holddown-interval setting does? It is limited to 255 seconds (4 minutes 15 seconds), though, and for BGP it is only allowed for EBGP sessions, not iBGP sessions. The documentation also says that you need to set holddown-interval on *both* ends. I'm gueesing that the holddown only prevents your end from initiating the BGP session, but that it will still accept a connection initiated from the other end. https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/bfd-liveness-detection-edit-protocols-bgp.html <https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/bfd-liveness-detection-edit-protocols-bgp.html> I haven't used BFD for BGP myself, though, only for static routes on a couple of links. But there I do use holddown-interval, and at least when I set it up several years ago, it seemed to do what I expected: after the link and the BFD session came up again, it waited (in my case) 15 seconds before enabling my static route again. -- Thomas Bellman, National Supercomputer Centre, Linköping Univ., Sweden "We don't understand the software, and sometimes we don't understand the hardware, but we can *see* the blinking lights!" _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
